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  1. /*
  2.  * Copyright (C) 2010-2018 Arm Limited or its affiliates. All rights reserved.
  3.  *
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  *
  6.  * Licensed under the Apache License, Version 2.0 (the License); you may
  7.  * not use this file except in compliance with the License.
  8.  * You may obtain a copy of the License at
  9.  *
  10.  * www.apache.org/licenses/LICENSE-2.0
  11.  *
  12.  * Unless required by applicable law or agreed to in writing, software
  13.  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
  14.  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15.  * See the License for the specific language governing permissions and
  16.  * limitations under the License.
  17.  */
  18.  
  19. /* ----------------------------------------------------------------------
  20.  * Project:      CMSIS NN Library
  21.  * Title:        arm_nn_mult_q7.c
  22.  * Description:  Q7 vector multiplication with variable output shifts
  23.  *
  24.  * $Date:        13. July 2018
  25.  * $Revision:    V.1.0.0
  26.  *
  27.  * Target Processor:  Cortex-M cores
  28.  *
  29.  * -------------------------------------------------------------------- */
  30.  
  31. #include "arm_nnfunctions.h"
  32.  
  33. /**    
  34.  * @ingroup groupSupport    
  35.  */
  36.  
  37. /**
  38.  * @addtogroup NNBasicMath
  39.  * @{
  40.  */
  41.  
  42. /**
  43.  * @brief           Q7 vector multiplication with variable output shifts
  44.  * @param[in]       *pSrcA        pointer to the first input vector
  45.  * @param[in]       *pSrcB        pointer to the second input vector
  46.  * @param[out]      *pDst         pointer to the output vector
  47.  * @param[in]       out_shift     amount of right-shift for output
  48.  * @param[in]       blockSize     number of samples in each vector
  49.  * @return none.
  50.  *
  51.  * <b>Scaling and Overflow Behavior:</b>
  52.  * \par
  53.  * The function uses saturating arithmetic.
  54.  * Results outside of the allowable Q7 range [0x80 0x7F] will be saturated.
  55.  */
  56.  
  57. void arm_nn_mult_q7(
  58.   q7_t * pSrcA,
  59.   q7_t * pSrcB,
  60.   q7_t * pDst,
  61.   const uint16_t out_shift,
  62.   uint32_t blockSize)
  63. {
  64.   uint32_t blkCnt;                               /* loop counters */
  65.  
  66. #if defined (ARM_MATH_DSP)
  67.  
  68. /* Run the below code for Cortex-M4 and Cortex-M3 */
  69.   q7_t out1, out2, out3, out4;                   /* Temporary variables to store the product */
  70.  
  71.   /* loop Unrolling */
  72.   blkCnt = blockSize >> 2U;
  73.  
  74.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  75.    ** a second loop below computes the remaining 1 to 3 samples. */
  76.   while (blkCnt > 0U)
  77.   {
  78.     /* C = A * B */
  79.     /* Multiply the inputs and store the results in temporary variables */
  80.     out1 = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++) + NN_ROUND(out_shift)) >> out_shift), 8);
  81.     out2 = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++) + NN_ROUND(out_shift)) >> out_shift), 8);
  82.     out3 = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++) + NN_ROUND(out_shift)) >> out_shift), 8);
  83.     out4 = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++) + NN_ROUND(out_shift)) >> out_shift), 8);
  84.  
  85.     /* Store the results of 4 inputs in the destination buffer in single cycle by packing */
  86.     *__SIMD32(pDst)++ = __PACKq7(out1, out2, out3, out4);
  87.  
  88.     /* Decrement the blockSize loop counter */
  89.     blkCnt--;
  90.   }
  91.  
  92.   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
  93.    ** No loop unrolling is used. */
  94.   blkCnt = blockSize % 0x4U;
  95.  
  96. #else
  97.  
  98.   /* Run the below code for Cortex-M0 */
  99.  
  100.   /* Initialize blkCnt with number of samples */
  101.   blkCnt = blockSize;
  102.  
  103. #endif /* #if defined (ARM_MATH_DSP) */
  104.  
  105.  
  106.   while (blkCnt > 0U)
  107.   {
  108.     /* C = A * B */
  109.     /* Multiply the inputs and store the result in the destination buffer */
  110.     *pDst++ = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++) + NN_ROUND(out_shift)) >> out_shift), 8);
  111.  
  112.     /* Decrement the blockSize loop counter */
  113.     blkCnt--;
  114.   }
  115. }
  116.  
  117. /**
  118.  * @} end of NNBasicMath group
  119.  */
  120.